1. Field of this Invention
This invention relates to the field of testing the blowout prevention apparatus of gas, oil, water and/or stream wells.
2. Prior Art
After a well has been drilled and the well casing is in place, ram-type blowout prevention apparatus is placed on top of the well casing. Or, such blowout prevention apparatus may be in place during drilling. Such blowout prevention apparatus has to be tested for leaks when subjected to high pressures eminating from within the well casing (i.e., high pressure gas, oil, etc.).
When the blowout prevention apparatus of a gas, oil, water and/or steam well is tested, one is usually involved with a well casing, a well casing segment mounted thereon, and a blowout preventer on the well casing segment. The blowout preventer has a pair of tube or pipe rams which are adapted to tightly seal around at least two pipes or tubes extending through the blowout preventer. A test plug is mounted in the well casing in a manner so that the test plug will not move any further into the well casing. Normally the well casing has a rim which prevents passage of the test plug. The two or more pipes or tubes extend through the center passage of a blowout preventer to a position past the pair of rams. There is also means for injecting fluid at high pressure, usually water, into the cavity formed by the central passage of the blowout preventer below the pair of rams, the central passage of the well casing segment and the central passage of the casing of the well casing above the test plug. The two or more pipes or tubes are blocked (or capped) on one end to prevent passage of the high pressure testing fluid. The high pressure test fluid allows checking for leaks, etc., around the tubes or pipes where contacted by the two rams. But this presents a very dangerous situation. The high pressure test fluid is used at pressures of up to 20,000 p.s.i. or so. The high pressure test fluid often forces or blows one or more of the tubes or pipes explosively up through the rams. The ejected tubes or pipes often cause serious damage to the surrounding well equipment and may cause serious bodily injury to personnel at the well site. In an effort to prevent the explosive ejection of the pipes or tubes, chains and the like are sometimes wrapped around the pipes or tubes and attached to nearby parts of the above ground well (drilling) structure'but this is a very unsuccessful procedure.